This application is based on and claims priority with respect to Japanese Patent Application No. 2002-173678 filed on Jun. 14, 2002, the entire content of which is incorporated herein by reference.
1. Field of the Invention
This invention relates to a sheet and an electronic apparatus using this sheet, and to a sheet and an electronic apparatus using this sheet capable of easily attaching and fixing a sheet to a base of an electronic apparatus and also easily separating and recycling the sheet at the time of scrap.
2. Description of the Related Art
Conventionally, in the case of fixing a substrate 52 for electric wiring to a cabinet 51 such as a frame or a body of an electronic apparatus 50, a pawl-shaped cut raised portion 53 which is a coupling unit provided in the cabinet 51 is used as shown in FIG. 11. That is, the cut raised portion 53 is provided with a step 54 for placing the substrate 52 and a twist portion 55 for fixing the substrate 52.
On the other hand, the substrate 52 is provided with a rectangular notch 56 which passes through the twist portion 55 of the cut raised portion 53 and also is placed on the step 54.
Therefore, the twist portion 55 of the cut raised portion 53 is inserted into the notch 56 of the substrate 52 and the substrate 52 is placed on the step 54 of the cut raised portion 53 and as shown in FIG. 12, the twist portion 55 upward protruding from the substrate 52 is twisted about 45xc2x0 to 90xc2x0 and the twist portion 55 is protruded from the notch 56 of the substrate 52 and the substrate 52 is fixed on the cut raised portion 53.
On the other hand, as shown in FIGS. 11 and 12, a sheet 57 made of paper, PET, resin, fiber, etc. for electrically isolating both of the cabinet 51 and the substrate 52 or insulating heat or magnetism according to the purpose is attached between the cabinet 51 and the substrate 52.
This sheet 57 is fixed to the cabinet 51 using the cut raised portion 53 provided for fixing the substrate 52 to the cabinet 51. For this purpose, for example, a slit 58 cut in I shape (see FIG. 14) is provided in a predetermined position of the sheet 57.
Therefore, in the case of attaching the sheet 57 to the cabinet 51, as described above, before the substrate 52 is attached to the cabinet 51, the cut raised portion 53 is passed from the lower portion to the upper portion of the slit 58 as shown in FIGS. 11 and 12.
As a result of this, as shown in FIG. 13, the cut raised portion 53 is sandwiched by restoring force of both side portions 58a of the slit 58 bent and raised by the cut raised portion 53 and the sheet 57 is fixed. Or, as shown in FIG. 12, the sheet 57 is fixed by further using adhesive means 59 such as two-sided tape or glue between the sheet 57 and the cabinet 51.
However, when the slit 58 is provided and the sheet 57 is fixed to the cut raised portion 53, in case that force acts on the sheet 57 and the sheet 57 is pulled, rupture 60 occurs from the ends 58b of the slit 58 as shown in FIG. 14.
Because of this, in comparison with a state before the rupture 60 occurs as shown in FIG. 15(A), after the rupture 60 occurs as shown in FIG. 15(B), there is a problem that restoring force for pushing both the side portions 58a of the slit 58 to the cut raised portion 53 becomes weak and the sheet 57 cannot be fixed to the cut raised portion 53.
Also, when vibration is applied to the cabinet 51, there is a problem that the sheet 57 flutters in both sides of the slit 58.
Further, when the sheet 57 is fixed to the cut raised portion 53 by the slit 58 and also the sheet 57 is directly attached to the cabinet 51 using adhesive means 59 such as tape or glue, there is a problem that material of the adhesive means 59 costs and an increase in cost is caused.
Also, there is a problem that it takes time and effort to peel the sheet 57 off the cabinet 51 at the time of scrap and is troublesome and also separability is wrong and it is unsuitable for recycling.
The invention is implemented in view of the problems described above, and an object of the invention is to provide a sheet which can surely be fixed to a base without using adhesive such as tape or glue and is excellent in separability at the time of scrap, and an electronic apparatus using this sheet.
In order to achieve the object, according to one aspect of the invention, there is provided a sheet which is attached to a coupling unit raised from a base and is placed on the base, the sheet comprising:
a slit portion through which the coupling unit passes is had, a width of the slit portion being formed smaller than a thickness of the coupling unit; and
rupture stops formed at both ends of the slit.
In this specification, paper, PET, resin, fiber, etc. are given as material of the sheet, but it is not limited to these as long as it is the material for performing insulation between a base and an electric wiring substrate.
Incidentally, the insulation means insulation required according to the nature of an electronic apparatus, for example, electrical insulation, heat insulation or magnetic insulation. Further, a sheet with high elasticity is preferably used as the sheet. Also, as a coupling unit, a cut raised portion in which a part of a cabinet is cut and is bent to the side to which the substrate is attached can be considered.
In the sheet constructed thus, a coupling unit for attaching an electric wiring substrate to a cabinet of an electronic apparatus is passed through a slit provided in the sheet. A width of the slit is smaller than a thickness of the coupling unit, so that the sheet is curled up in both sides of the slit by the coupling unit.
Because of this, the sheet tends to return to a flat state and grasps the coupling unit by this restoring force. As a result of this, the sheet is fixed to the coupling unit.
Incidentally, when both sides of the slit are curled up by the coupling unit, force by which the slit is further caused to be ruptured acts, but rupture can be prevented by rupture stops provided in both ends of the slit.
As a result of this, the sheet can surely be fixed to the coupling unit.
According to another aspect of the invention, the rupture stop is an opening formed in a shape without a stress concentration portion or a rupture stop slit inclined to a rupture direction acting on the slit end.
Here, openings with circle or ellipse are given as the opening without a stress concentration portion. In addition, it may be an opening in which the whole shape is rectangular shape and corner portions are rounded.
Also, the rupture stop slit inclined to a rupture direction acting on the slit end means a rupture stop slit inclined to a slit orthogonal direction which is a rupture direction.
Therefore, a rupture stop slit provided straight and slantingly in the slit end, a rupture stop slit provided in Y shape forked from the slit end, etc. correspond.
Incidentally, one end of a slit may be formed in a circular opening and the other end may be formed in a Y-shaped rupture stop slit.
The sheet constructed thus attempts to widen the slit end when the coupling unit passes through the slit, but rupture of the slit is prevented by the opening or the rupture stop slit inclined to the rupture direction, so that the sheet in which both sides of the slit curl up grasps the coupling unit and the sheet can be fixed.
According to another aspect of the invention, a hold sheet which has the same material as that of the sheet and has a through sheet passed through the coupling unit is placed with the hold sheet overlaid on a range including the slit and the vicinity of its slit.
In the sheet constructed thus, a hold sheet in which a slit similar to that of the sheet is provided is overlaid on the sheet to grasp the coupling unit, so that the sheet can be fixed surely.
Also, the hold sheet having the same material as that of the sheet is used, so that separation at the time of scrap is easy.
According to another aspect of the invention, there is provided an electronic apparatus which has a base and attaches an electric wiring substrate by a coupling unit raised from this base and provides a sheet placed between the base and the electric wiring substrate, wherein the sheet has a slit in which a width is formed smaller than a thickness of the coupling unit and rupture stops are formed in both ends, and the slit is passed through the coupling unit so as to be raised from the base.
In the specification, paper, PET, resin, fiber, etc. are given as material of the sheet, but it is not limited to these as long as it is the material for performing insulation between a base and an electric wiring substrate.
Incidentally, the insulation means insulation required according to the nature of an electronic apparatus, for example, electrical insulation, heat insulation or magnetic insulation. Also, a sheet with high elasticity is preferably used as the sheet. Also, as a coupling unit, a cut raised portion in which a part of a cabinet is cut and is bent and raised to the side to which the substrate is attached can be considered.
In the electronic apparatus constructed thus, a coupling unit for attaching an electric wiring substrate to a cabinet of the electronic apparatus is passed through a slit provided in a sheet. A width of the slit is smaller than a thickness of the coupling unit, so that the sheet is curled up in both sides of the slit by the coupling unit.
Because of this, the sheet tends to return to a flat state and thereby grasps the coupling unit by this restoring force. As a result of this, the sheet is fixed to the coupling unit.
Incidentally, when both sides of the slit are curled up by the coupling unit, force by which the slit is further caused to be ruptured acts, but rupture can be prevented by rupture stop portions provided in both ends of the slit. As a result of this, the sheet can surely be fixed to the coupling unit.
According to another object of the invention, there is provided an electronic apparatus having a protrusion being capable of engaging the slit at the side of the coupling unit.